The invention relates to an optical exposure device, in particular a UV table lamp, for hardening light-hardening gel in the course of finger nail treatment, having at least two UV light sources which are arranged in a V-shaped fashion and are arranged above a bearing surface for a hand with the finger nails to be treated, and define a common light source plane, and having a light source housing.
An optical exposure device of the design described at the beginning has been disclosed by DE 37 27 916 C2. The radiating source implemented here is designed symmetrically relative to the housing longitudinal plane and describes an arcuate section of at least 180xc2x0 with the opening of the arcuate section pointing towards the insertion opening. The aim of this is for the optical exposure to be limited essentially to the region of the finger nails and otherwise to be able to provide it uniformly both for the left hand and for the right hand.
Other optical exposure devices are described in DE-U 86 09 293, DE-U 298 08 796 and U.S. Pat. No. 5,130,551. Moreover, optical exposure devices are used in practice to harden an light-hardening gel in the course of finger nail treatment. These operate generally in such a way that all (five) finger nails of one hand can be treated simultaneously. For this purpose, the optical exposure devices known in practice are constructed as tunnels and are equipped with at least four UV light sources, as is described in principle in DE-U 86 09 293 already mentioned above.
In order to supply these light sources with power it is regularly necessary to have recourse to two or more reactance coils which act as AC resistor and convert the system voltage present (regularly approximately 230 V or 110 V) into a suitable operating voltage (usually approximately 60 V to 100 V). In any case, the design outlay is high. Resulting from this there is also a high production cost which is explained, in particular, by the use of four UV light sources which are expensive owing to their special equipment for the intended use. A comparable statement holds for DE 37 27 916 C2, whose radiating source has a complicated shape and is likewise represented by at least four individual tubes. The invention is intended to provide an overall remedy here.
The technical problem on which the invention is based is to develop an optical exposure device of the generic type such that said device is of a design configuration which is simpler (than the previously known prior art), operates in a particularly power-saving fashion and permits mounting to be easy and quick. Overall, the production costs are intended to be substantially reduced.
In order to achieve this object, the invention proposes in the case of an optical exposure device of the generic type that the bearing surface (for the hand with the finger nails to be treated) is of convex curvature, and that the (only two) UV light sources are inclined with respect to the light source plane, the associated angle of inclination assuming values of between approximately 30xc2x0 and 60xc2x0. Of course, it is also possible to implement more than two UV light sources within the scope of the invention, although this is not expressly necessary. Rather, it has emerged that by comparison with the prior art (four UV light sources), it is possible virtually to halve the number of light sources required within the scope of the invention without observing any losses in quality in the finger nail treatment or a lengthening of the treatment period. This can be ascribed essentially to the fact that the bearing surface is of convex curvature and the two UV light sources have the described inclination with respect to the light source plane defined.
As a rule, the V angle enclosed by the UV light sources can have values from 30xc2x0 to 60xc2x0,preferably approximately 45xc2x0. The vertex of the V angle is generally arranged in an extension of the finger nails to be treated. The angle of inclination of the two UV light sources with respect to the light source plane defined is preferably approximately 45xc2x0.
As a result, in combination with the bearing surface of convex curvature this special arrangement of the two UV light sources achieves the desired effect of reducing costs and simplifying design. The point is that the arrangement is made such that the vertex of the abovenamed V angle is generally arranged in the region of the longest finger tip (middle finger). The V shape in this case ergonomically matches the five finger tips forming a V-shaped envelope, with the result that the exposure exactly follows the natural position of the finger nails. As a result, the light-hardening gel can be hardened in a pinpoint and an effective fashion.
The light source plane is principally of horizontal alignment and arranged at a prescribed parallel spacing above the bearing surface. If the two UV light sourcesxe2x80x94generally with the same angle of inclinationxe2x80x94are tilted or inclined with respect to the light source plane in a fashion facing one another, the result is that they enclose in a respective extension a head angle of a triangle having the angles of inclination as base angles. It is particularly advantageous when the two UV light sources are constructed as U-shaped gas discharge lamps with a foot designed as a plug-in unit. The point is that this foot can then be pushed into a slotted receptacle of a housing web for respectively positioning the UV light source. Consequently, the result of this is not only that the mounting is simplified (because a simple plug-in unit is implemented), but additionally thatxe2x80x94as it were, automaticallyxe2x80x94the described positioning according to the invention of the two light sources is also achieved. The housing web previously described can be stabilized by means of lateral steel inserts. The latter can, for example, be inserted into associated web pockets, or be bonded, riveted or connected in a comparable way to the housing web. Because they are fitted near the circumference on a housing base of the light source housing, these steel inserts increase the tilting moment of said housing, and thus the stability.
Use is made as voltage supply for the two UV light sources of an external plug-in ballast with a dedicated plug housing and at least one built-in reactance coil as AC resistor. As a result, the design outlay is reduced once again, precisely because it is possible only to have recourse to a single reactance coil as AC resistor, and there is no need for a plurality of devices of this type as required in the prior art. Moreover, a timer module can be fed from the supply voltage for the UV light sources. Said module serves for automatically switching off the UV light sources after a selectable treatment time. Consequently, comfort functions can be represented unchanged in conjunction with an extremely simple design.
The light source housing for the optical exposure device described is for the most part designed in two parts with a housing base and housing hood. The two abovenamed components can have a round to elliptical base surface, with the result that a shapely, futuristic appearance is achieved over all. The outlay in terms of production is reduced once again by virtue of the fact that, according to a preferred embodiment, the housing base and housing hood are latched with one another. Of course, other connections, for example screwed or bonded connections are also conceivable. The two above-mentioned components are designed as plastic injection molded parts in order to permit quick and flexible production in conjunction with low costs. The housing hood has an insertion opening in the shape of a circular arc for the hand to be laid down in order to render it possible for the hand or the fingernails thereof which are to be treated to be inserted acceptably into the light source housing and laid down therein.
The bearing surface of convex curvature has a central support, of convex cross section, for the back of the hand and two finger support webs on both sides so that the hand can be laid down without being cramped, the previously described V shape of the finger nails automatically resulting. In addition, it is achieved hereby, in particular, that the outer fingers with the associated fingernails, that is to say the small finger and thumb, assume an exposed position, in particular are not negatively influenced as regards the light intensity by virtue of the other fingers casting a shadow or the like.
The previously named finger support webs can directly adjoin the central support for the back of the hand with bearing ramps. Usually, the bearing surface (in conjunction with the finger support webs) is constructed in plan view is an essentially elliptical fashion and with mirror symmetry relative to a major axis (of the ellipse), so that, as a result, the same exposure conditions are to be noted when treating the left and right hands. In any case, the finger support webs regularly take over the task of serving as support for the small finger and the thumb, or vice versa, depending on whether the left or the right hand is being treated. The exposed position of the latter, and the additional support ensure that, in conjunction with the V-shaped arrangement of the two UV light sources intensities of light and/or exposure which are comparable over all with regard to the V angle and the angle of inclination, are present in the region of each individual finger nail. This leads to uniform and quick hardening of the light-hardening gel applied.
All the previously described effects and actions are achieved in conjunction with the construction of extremely simple design, and with economic production, with the result that substantial cost advantages are to be noted by comparison with the prior art. Again, the recourse to only two UV light source reduces the development of heat. At the same time, scattering effects or other electromagnetic interference are minimized. This is where the essential advantages of the invention are to be seen.
The invention will be explained in more detail below with the aid of the following drawings which represent only an exemplary embodiment:
FIG. 1 shows a perspective view of an optical exposure device according to the invention;
FIG. 2 shows the subject matter according to FIG. 1 with the housing hood removed;
FIG. 3 shows another view of the subject matter according to FIG. 2;
FIG. 4 shows a section through the subject matter according to FIG. 1 in the region of the bearing surface;
FIG. 5 shows the power supply device for the optical exposure device; and
FIG. 6 shows a simplified sketch of the voltage supply according to FIG. 5.